Safety door bolt



Feb. 5, 1929. 1,701,302

' c. A. GRIFFITH I SAFETY DOOR BOLT Fi1ed Nov. 15. 1926 2 25- am Charles H. Griffith arfonwqd) Patented Feb. 5, 1929 onantns A. GRIFFITH, or SEATTLE, WASHINGTON.

SAFETY DOOR BOL'L vApplication filed November 15, 1926. Serial No. 148,456.

My invention relates to an improvement in safety door bolts of the type which permit a door ,to be slightly opened, sufficient to observe who maybe outside, but not sufficient to permit the entrance of a person. t

' To this end it is designed to prevent forcible entrance of anyone-whom it is desired to exelude, and to be so constructed and so located that it is altogether unobtrusive, so that it maybe conveniently operated by one in the a door, yet out of the way forv act of opening and one which will act pos1- ordinary use,

1 tively and quickly to stop the door, yet which may be-released as quickly and simply; also, to provide such a stop which automatically maintains itself in locking position so long as no positive action is taken to retractit.

.Another object is the provision of such a device which willbe simple and yet strong, and which can be so located that it cannot be subjected to tampering.

My invention comprises the novel parts and the novel combination and arrangement thereof as shown in the accompanying drawings, described in this specification, and as defined in the claims terminating the same; and it comprises further the novel arrangement' of such a device relative to the door and other parts of the building, all as will be brought out hereinafter.

- In the accompanying drawings I have shown my device in forms which are now preferred by me, and arranged as I deem it most suited to the end in view. V

Figure 1 is a section on a horizontal plane through the door, its frame and the adjoining walls, showing the location of my device withframe; V

Figure 2 is a section on a vertical plane through the frame and joists, showing my device in side elevation;

Figure 3 is a section through'a modified construction of a detail of my device.

It is an important obj ect to provide. a bolt which cannot mar the beauty of a doorway and which is inconspicuous, and which can therefore be employed without showing obviously to a caller that it is being used, and

which can yet stop the door effectively and prevent the intrusion of one whose presence is not desired. To that end I locate my device within or beneath the floor of a house, adjacent the door which is to be stopped, and adjacent its frame. The door 9, as illustrated best in Figure 1, is hinged at 90 toione side 91 of the frame, and its swinging edge rests normally against a stop carried by the opposite side 92 of the frame. It is necessary to permit the swinging edge of the door to open partially to observe who may be calling and to determine whether or not it is desirable to admit the caller, and yet it is not desirable to allow the door to swing far enough to admit a caller if it is determined that his presence is undesirable. I, therefore, provide a stop 1, formed as a strong steel rod,

which normally lies flush with the floor 8 of the building but which is proje'ctable vertically into thepath of the door. A striker plate may be employed to'co-operate with the stop 1 and to prevent its marring the door. This stop 1 should be located far enough inward from the swinging edge of the door that it may not be readily reached by one who desires to gain entrance, and at such a position that it will permit the door-to open only sufficiently for oneinsideto see who the visitor may be and to learn his business.

To operate the stopl, which, as has'been stated, is normally flush with the floor 8, I provide a plunger or button 2, which normally projects above the surface ofthe floor i 8 and which is located adjacent the side 92 of the door frame, that is, close to the frame,

where it is outof the way and yet in position to be stepped upon by one answering the door. This button2 is connected to the stop .1 by suitable means, as, for eXample,the links 20 and 10connecting the button 2 and stop 1, respectively, to opposite; ends of a lever This lever is pivoted at 30 upon a bracket 31,

which may be supported upon the joists 80 in the .floor and relative to the door and itsfof the building, and I prefer that the arms of v with the stop 1 is pivoted to the long end of the lever 3.

It will be evident now that merely by stepping upon the button2, placing the foot as would be natural in opening the door, a-

person may raise the stop 1 far enough to effectually stop the door 9, and so long as the stop 1 remains projected, the door may: not be swung open further. If it is desired to admit the visitor, it is only necessary to step back ofthe door slightly and to depress the stop 1, whereupon the door is free to swing open.

It will thus be seen that it is desirable to provide some means of maintaining the stop 1 raised, even though pressure is removed from the button 2. To this end, I may provide felt washers 4 surrounding either the stop 1 or the button 2, or both. This or any equivalent friction means applied to either of these members, or applied to any part or" the connection betweenth'eln, will serve to maintain the bolt 1 raised until it is positively depressed. I have shown in Figure 3 an equivalent means as, for example, the spring 41 secured at one end 42 within a ferrule 24 surrounding the plunger 2 and bearing against this plunger to hold it frictionally in any selected posi tion. It will be clear that the same means might be applied to the stop '1.

In order to permit adjustment of the normal height either of the plunger 2 or the stop 1, I may thread the link 20, or its equivalent link 10, within the corresponding member, the plunger 2, or the stop 1, as is indicated in Figure 3.

There is thus provided a device which is simple to install, which is inconspicuous, and which is yet thoroughly el'lective under all conditions to prevent the entrance of one whose presence is not desired, and which can be intantly operated to admit one whom it is desired to admit.

What I claim as my invention is:

1. A safety door bolt comprising a stop and a plunger adapted to be set into and to project from the floor, means connected to each of said plunger and stop to project one as the other is depressed, and tending to maintain the one balanced against the other, and triction al means for retaining either said plunger or said step projected above the floor.

,2. A safety door bolt comprising a sto and a plunger adapted to be set into and to project from the floor, a lever connecting said plunger and stop and pivoted between its ends, and so balanced as to tend to remain in a netural position, and frictional means for retaining said step projected above or depressed below the floor.

3. A safety door bolt comprising a stop and a plunger adapted to be set into and project trom the floor, and a lever connecting said plunger and stop, and pivoted between its ends, the arms 015 the lever being unequal, and the longer arm connecting with the stop, whereby the stop is materially projected by a lesser depression of the plunger, and means for substantially equalizing the moments of the two lever arms and associated parts, whereby the mechanism will tend to remain in a selected position. I

4-. A safety door bolt as in claim 3, together with frictional means for maintaining it in a selected position. a q

5. A safety door bolt comprising a stop and a plunger adapted to be set into and to project from the floor, means connecting said plunger and stop to project one as the other is depressed, and means for adjusting the top of said members relative to their connecting means and relative to the floor level.

6. In conil'iination with a door frame, a door hingedly supported therein by one edge, and a floor, a satetybolt for said door comn-ising a stop projectable upwards from the floor within the path of swing of said door, to intercept said door and prevent its swinging open suflicient to permit entrance, anopcrating means for said stop located adjacent the door frame at the swinging side of the door, and operative connections between said means and the stop. I

Signed at Seattle, King County, WVashington, this 10th day of November, 1926.-

CHARLES G IFFIT 

